The present invention relates to a plasma processing method and apparatus. More particularly, the invention relates to a plasma processing method and apparatus for generating a plasma using microwaves to subject a substrate to be treated, such as a wafer, to a plasma processing, such as an etching or filming treatment.
As an example of a microwave plasma processing apparatus of the prior art, there is an apparatus using a cavity resonator and a slot antenna arranged at a right angle with respect to a surface current flowing through the bottom of the cavity resonator, as disclosed in EP-A-0674334. By making use of a slot antenna, the apparatus is constructed to radiate microwaves from the slot antenna in the same mode as that of the microwaves in the cavity resonator, thereby to generate a plasma.
A conventional apparatus of the slot antenna type, as disclosed in U.S. Pat. No. 4,776,918 and U.S. Pat. No. 5,134,965 for example, is provided with slot antennas which are disposed in contact with or set close to a microwave penetrating window for introducing microwaves into a processing chamber so that the processing chamber can be evacuated.